Spring suspension system for motor vehicles



- 9 7. March 1 2 F. L. OLWADSWORTH SPRING SUSPENSION SYSTEM FOR MOTOR VEHICLES Filed July so. 1920 Y 4 Sheets-Sheet 1 F. LVO. WADSWORTH SPRING SUSPENSIWN SYSTEM FOR MOTOR VEHICLES and July so. 1920 4 sheets-Sheet 2 INVENTQR 0. Mash 0W7? March 29, 1927. 1,622,891

F. L. O. WADSWORTH SPRING SUSPENSION SYSTEM FOR MOTOR VEHICLES Filed July 30. 1920 4 s t sh t 3 o --c 4930 B! 6 I? B 67 72 Z Z y-Ifl I 1927. J 1,622,891 March "F. L. o. WADSWORTH SPRING SUSPENSION SYSTEM FOR MOTOR VEHICLES Filed July so. 1920 4 Sheefs-Sheet 4 4 frag/vs)- V Fig. 1.

Patented Mar. 29, 1927.

onrusn' s'r ares FRANK L. 0. WAD SWORTH, OF

1,622,891 A Ti-EENT @OFFI'CE.

PITTSBURGH, rE'NNSYLvANIA.

SPRING SUSPENSION SYSTEM ron moronvnmonns.

Application filed July 30,

Myinvention'relates to elastic suspension systems for vehicles, and particularly to those types of organization which comprise combinations of relatively heavy and stiff main, springs with con'lparatively light, pliant and long range secondary, or supplemental, springs interconnected and conjoined-to act either concurrently or successively, inipara-llel or in ser1esby means of rocking lever or F bridge members; and

which are, for thatreason, generally designated as lever-acturated-supplemental spring systems.

Thegeneric object oi this invention will be best understood by referring to the diagrams of Figs. 1,2 and 3. ;In an ordinary main spring suspension (such as is conveniently indicated in Fig. l) the center of the resilient leaf element 1, is bolted, or other wise rigidly Secured, to one of the'relatively movable members of the vehicle chassis (e. g., the body or tonneau); and the ends of this element are flexibly coupled to the other of the relativelymovable chassis members (e.'g., the axle) by means of swinging shackle links '22. The initial unloaded dorm of this spring is shown in Fig. 2 and is indicated by the dot-ted lines AA of When the vehicle body is subjected toits normal load the main spring isvsomewhat flattened and the parts assume the position indicated by the lines BB. \Vhen either of-the chassis members is subjected to a'sudden shock whichtends to force it toward the'other member, the compression stress on thespring is increased; and the element l$"lill1'tll91' flexed or bentto the form shown in the lowerline (C) of the diagram. This increased fiexure imposes a reactive strain, K, on the suspension system, which is in excess of the normal load strain, N;

and as-soon as the effect of the compressive o we]: has been absorbed or neutralized by this increasedelastic strain in the spring, thelatter tends to immediately recoil or expand to its initialposition. But this return movement imparts a swingt0 the chassis members that will, in most cases, carry the parts above'the normalload position, B, and even beyond thelposition A; and in such cases the main spring is subjcc'tcd to an opening or a rebound Stress that tends toshorten, and bend it' negatively to the form shown in the upper line, D,

"of Fig. 1. Under such circumstances a re verse strain is imposed on theindividnal 1920. Serial No.400,256.

leaves of the spring which helps to check the separation of the body and axle-parts, but which is detrimental to the resilience and the life ofthe elastic suspension member.

The degree, or amount, of positive and negative bending of the main leafspring for a given movement ofapproach or separation ofthe body and axle parts-maybe diminished by the use of a Supplemental lever-actuated spring in Series with the said main spring. In such a combination the secondary lever-spring system, 3, is ordinarily interposed between the main spring shackle support 2 and that part of the vehicle to which said support is 'usually attached; as shown inthe right hand portion of Fig. 1. When this organization is subjected to compressive stresses the supplemental spring is flexed by the'downward movement of the main spring and lever sys tem 152-3; and i the parts assume a position indicated by the lines C C 0, in which the two elastic elements are conjointly subjected to positive strains, K and is, that tend to restore the members to their initial load'posit-ion B"-Bb. But the freerecoil and subsequent rebound of the springs will-carry-the members beyondthe loci of static equilibrium to the position DDcl,

in which the main springis subjected to a reverse or negative bending stram R, that is not ordmarly accompamed'by any cooperative secondary spring resistance,but is,

onthe contrary,'usually opposed inpartby someunexpended positive straln 1' 1n the expanding supplemental spring.

In consequence of these characteristic features of operation the supplemental spring suspension systems last considered have a W'lClGI'tlIlQQ of flexibility and a very effective action in restraining and absorbing amples of such construction are disclosed in the Hassler Patents Nos. 1,130,897 of March 9, 1915 and 1,149,756 of August 10, 1915; and also in applicants copending applications Serial Nos. 358,817 of February 16, 1920, and 389,337 of June 16, 1920. But in all of these constructions the main leaf spring element, 1, of the combination, is eitherpositively constrained, or freely permitted, to expand or flex negatively beyond its free unloaded form, A, when the body and axle parts rebound, or separate, considerably beyond the position of static equilibrium B.

A primary object of my present improvements is to provide a main and supplemental spring combination in which the primary elastic element is prevented from expanding or recoiling beyond its initial unstrained, or unflexed, form; and is thereby guarded against distortion, or breakage, or loss of resiliency that may result from the negative bending, or the repeated reverse flexing of the main spring leaves or libres. In the principal embodiments of the invention hereinafter disclosed this feature of improvement is further emphasized by the establishment of a positive bending or compression stress on the main spring element in all stages of opera tion, and in all positions. of the spring support system; and the general purpose of this characteristic of my improved organization is the elimination of the negative bending being of the primary spring on rebound movements, by the continued maintenance of a positive fiexure strain therein.

Another important purpose of certain generic exemplilications of my invention is the invention is the provision of a main and supplemental spring combination of such a character that both of the elastic suspension elements are cooperatively and conjointly subjected to positive, or increasing, flexures When the spring supported parts move in either direction from the normal load position-of static equilibrium and such movements (both of com Jression and separation) are thereby resistec and checked by a continually and progressively increased strain in both the primary and the secondary spring elements.

A fut-her object of my present improvements is to provide a composite spring support system in which the primary and secondary suspension elements are connected and conjoined in such manner as to most effectively utilize the flexural action of one spring in checking and controlling the cooperative flexure of the other, so as to prevent or restrain any undue, or excessive, elastic distortion of either, or both, of the resilient suspension members of the combination.

The general manner in which the above described features of organization can be functionally utilized in conjunction with a main leaf spring support is shown in the diagram of Fig 3. In this illustration the two lower curved lines BB, and CC" show the form and position assumed by the main spring under conditions of normal load and kinetic compression stress respectively; and the arrows a-n and -75 indicate the points, and the direction, at and in which the supplemental spring strains are preferably applied, to and through the main spring, in order to assist the coacting tensions, N and K, in sustaining the applied load stresses. The two upper lines E-E and E" E indicate the position and form assumed by this same main spring element of myimproved combination, when the parts rebound to varying heights above the normal line B-n-N nB; and the arrows R, and rr, indicate the loci and the directions in which the primary and the secondary spring resistances are then constrained to act in effecting the quick arrest of such recoil movements. A comparison of the strain lines E-1'-R-1 E, with the dotted line D-DD, (which corresponds to the line D D of Fig. 1) indicates very clearly the fundamental and essential diflercnces between the nonreversed or irreversible spring action of my improved organization, and the reversed or reciprocal bending action that Cilftl'ittftellZGS the operation of main and supplemental spring combinations heretofore used; and also indicates the marked effect of this improved action in restraining and decreasing the extent of the rebound or overthrow of the parts beyond, or above, the normal position of static equilibrium.

Another more specific object of my present improvements is to provide a combination of the general character above described with means for lengthening or damping the free period of recoil movement of the compressed spring system; thereby further retarding and checking the rebound of the parts from, and beyond, normal load position; and also stabilizing the system by diminishing the tendencies of the body to sway laterally or pitch longitudinally under the effect oi large vertical oscillations.

A further specific object of these improvements is the utilization of a particular form of fluid damped double acting supplemental spring lllGL'lHLlllSlTl, in conjunction with a frictionally damped double acting main spring, for the purpose of securing an extremely sensitive elastic suspension system which is not subject to quick recoil movements, and which is capable of resiliently absorbing shocks of any magnitude, and of effectively restraining and quickly checking either vertical or lateral movements of the spring connected and supported parts.

Other additional objects, and further specific characteristics, of certain exempli- 'fications of "this invention will be made apparent by the following description of the various illustrative embodiments thereof that are depicted in the accompanying drawings, in which:

Figs/1 and 2 are, as'previously explained, diagrammatic illustrations ofthe form, and mode of action, of an ordinary leaf spring, when the latter is used eitherby itself or in 'conjimction'with the usual type of supplemental spring end supports, as the elastic suspension member of a vehicle body; Fig. 3 is 'a corresponding illustration of the functional action otsuch a leatspring support when it is made a part of my improved organization; Fig. 4 is a general semi-diagrammatic showing of one form of my im- :provements"asapplied to the front crossleaf-springsuspension of a Ford type of car; Fig.5 isa; view (partly in section on thejplane 55 ofFig. 7) of a modified form of'the construction shown in Fig, 1; Fig. 6 is an elevation of the organization of Fig. 5

with the parts in the position assumed on rebound Fig. 7 is a sectional View on the plane 7'7of Fig. 5;'F1g. 8 1s a plan view of afpart'o'tthe construction shown in Fig.

5;Figj9 is a cross section through one of the supplemental spring elements of this mechanism; and Flg. 10 1s a diagram-on an enlarged scale-showing the operative action of certainp'arts of the organizations ill'u'strated'in'Fig. 4, and Figs. 5 to 9 inclusive.

On thesec'ond sheet of drawings: Fig. 11 is an elevation of another embodiment of my invention "asappliedto a cross leaf spring support; Fig. 12 is a second viewof this same construction, which is partly'in section onthe plane 1212 of Fig. 14;, and which shows'the parts'in the position they assume under a kinetic compressive stress; Fig. 13 is an enlarged sectionalflelevation on the plane 1*313 of Fig, 14, and illustrates the parts of this'construction inthe position assumed on rebound movement; Fig. 14 is a plan view ofthe construction with the parts in the position sh'ownin Fig. 13; Fig. 15 is a diagram (similar to that of Fi'g. 10) illustratdug the various successive positions taken bythe conjoined elements ot'the orgaiiization depicted'in'Figs. 11 to ll inclusive; Fig,

1G 'is'a sectional side View of another exemfpli'ficatio'n' of my'improvements as applied to-a side leaf spring suspensionthe parts being here shownin the position which the assume under an excessive'reb'onnd or recoil {movement and Fig. 17 is a side elevation ona reduced scale) of the construction of Fi'g. 1'6 with the pa1'ts i11 the position assum'edby them under kinetic compressive Fig. 22 is an elevation -partly in section o't an exemplification of my improvements applied to another cross leaf spring-suspension; Fig. 23 is a sectional end view on the plane 2323 otFig. 22; Fig. 24 is a diagram illustrating the functional action of the parts shownin Figs. 2223; andFig. 25 is a sectional elevation (on a central longitudinal; plane) of a modification of the last men tioned organization as it might be used in conjunction with a sideleaf spring support.

On the fourth sheet of drawings -I-have illustrated another species of the present invention: On this sheet Fig. 26'is' asectional elevation, on the vertical longitudinal plane through the center of the main cross leaf spring, of one exemplificatio'n of this species of construction; Fig. 27 is=a view showing the-parts ofthe said construction in the position assumed on rebound; Fig.

28 is a view, on the plane 2828 of Fig. '26; i

construction shown in Figs, 2 6"to 29, as

applied to a side leaf spring mount-ing;-F igs. 31 and 32are two similarviewspf-another embodiment of my present improvements as applied to a rear cross leaf spring suspension of a Ford car {Fig.33is-a side elevation (partly in section) of the species of construction shown inFigs 31 and 32 as utilized "in conjunction with a three-quarter elliptic side spring system; and 34 is an end view, partly in sectionQon'the plane 34q34 of Fig.

In the form of construction illustrated in Fig. 4, the primary suspension element is provided witha pair of secondary helical springs 4;,which are mounted symmetrically one on each side of an intermediate flexible portion of the main leaf spring 1, and are connected theretoby suitable clip and follower bolt connections, (S 8 8 etc-.. that maintain these springs under a ;predeter-' extremity of a forked lever 3 by means of the cross head 9'and thete'nsion bolts '10. The lever member 8 is pivotally mounted in the aXle'perch-boss, 11, and is connected, at-an 44 are operatively" en'gaged with' the inner intermediate point of its -length, with e links 2) and to the body of the vehicle (or.

to the center of the main spring) by means of the one way or single acting rod and crank connections 1617, 2122.

When the parts are subjected to static load stress the lever 3 is in operative engagement with both extremities of the initially tensioned supplemental spring 4, and the arms of the bridge lever 14 rest on the cylindrical upper surface of the boss support 11. If now the system is subjected to an increased kinetic load or compressive shock which tends to force the main spring and axle support toward each other-the interconnected lever elements 3 and 1 1 are rocked, as a unit, on the pivot bolt mounting of the lever 3; and the cross head, 9, is raised toward the upper dotted line position shown in Fig. 4. The upward n'iovement of this head and the concurrent downward move ment of the main spring 1, forces the opposite extremities of the supplemental springs 4: toward each other. and imposes an increased compression strain thereon; and this movement and action continues until the main spring and lover parts have been carried from the full line position l5-Bbb, to the dotted line position CU-c 0, and the cross head 9 has been brought into cont act with the lower face of the main spring 1. After this engagement occurs the conjoined springlever-system is locked against further relative movement, and any additional dis placement of the spring supported parts is resisted by the positive flexure and flattening out of the main spring alone.

During the above described compressive movement the lower end of the rod 22 slides freely through the aperture in the short arm of the bell crank member 21; but as soon as the parts have returned to normal load position (B), the elements 16--17-21-22 are brought into tensioned engagement; and any rebound, or separation of the body and axle members, imposes an outward thrust on the rod and pin connections l(l17 that tends to rock the lever members 3 and 14-2 in a clockwise direction on their respective pivot supports 11 and 15 as shown most clearly in the dia ram of Fig. 10. This action lifts the bridge member .14: out of engagement with the boss 11, and thus permits the connected lever elements to be actuated dilferentially in accordance with the relative re sistances to their respective movements. The downward movement of the lever 8 depresses the upper extremities of the supplemental spring a (which are connected thereto by the bolts 10) and the upward movement of the arms 14 lifts the outer extremity of the main spring 1 more rapidly than the center of that spring is raised by the rebound of the body. The complementary and opposite movements of the supplemental spring connections, 9-10 and 68, (with the l ver and main spring respectively) again imposes an increased compression on those secondary resilient elements; and the cooperative and conjoint reaction of the bridge lever connections with the extremity of the primary spring, also imposes and maintains a positive bending strain on that suspension element; and as a result of these concurrent or successive interactions. the rebound, or separation of the parts beyond normal load position, is accompanied and resisted by the positive or compressive flexure of all of the spring suspension members. This fiexure, of both the supplemental springs l and the main leaf spring 1, is progressively increased as the separation of the body and axle members continues, until the parts have moved to the dotted line position EE-ee; after which the lever 3 is locked against further movement (by the engagement of its head, 9, with the axle); and any additional separation of the aforesaid chassis members is resisted and checked by the continued upward swing of the bridge lever let that carries the end of the main spring toward the position E (see Fig. 10) and thereby subjects that element to a greatly increased compression.

Figs. 5, 6 and 7 illustrate, in somewhat greater detail, another organization that presents the same general arrangement of parts as is shown in Figs. 4 and 10; but which differs from the construction first described in the specific character and disposition of the supplemei'ital spring elements. In this modi ied en'ibodiment of my improvements these secondary resilient members are made in. the form of relatively flexible multiple leaf spring 262T27, which are mounted, at their inner adjacent ends, in rigid clips 29 and Slo -30 that are pivotally supported on an intermediate flexible portion of the main spring 1, by means of the bracket and cross bolt connection 3132. The outer extremity of the lower spring 26 bears directly against the lower face of the main spring 1; and the adjacent ends of the two upper springs 27'27-which are symmetrically disposed one on each side of the main spring as shown best in Fig. 7are cross connected by a pin, 33, which engages with the upper face of the said main spring. The central portions of the single secondary leaf element 26 is provided with an elongated bearing clip 36 that is adapted to make sliding engagement with the head 9 of the lever ele ment 3"; and the corresponding portions of the twin leaf springs 2727 are operatively connected with this head by means of the clips 3'78T, the slotted shackle links 39-39, and the cross bolts 38 and 10. The lever B is rockably supported on the axle perch bolt 11*;and'is-flexibly coupledto the endot the main spring 1 by means of the doublearm bridge lever 14 and the U shaped shackle link 2; and this bridge member is coupled, in

turn, to the bracket support, 29, (or, if desired, to the vehicle body) by the oneway toggle joint connections 1617 21 22 22; all of the last mentioned parts being either identical with, or substantially the same as, the correspondingly numbered parts of my Fig. 1 construction.

When the parts are assembled in operative relationship the secondary resilient elements are under sui'licient initialtension to maintain the parts in the normal load position'show-n in full lines in Figs. 5, 7, and 8;-

andin this positionthe lever system 3*-l4 etc. is in double connective engagement with both of the supplemental leaf spring members, 26 and 27'27, and with the toggleiVhen the body and axle members are forced toward eachother by an increased'load, or by an-added joint system 16 to 22 kinetic stress, the lever elements 314 are rocked as a unit on the pivot bolt support:

locked against further relative compressive movement, and are then flexedor bent as a unit by any additional closure otthe system.

During the continuance of the action last described the head 9 is out oi engagement with the upper. pair of supplemental springs 27.27; but the latter are maintained in tensionedengagement with the main spring by the pin 41' which prevents the upward movement ol the shackle connection 39 with the head 9 When the parts return to their initial positionv of static equilibrium the cross bolt; 40 engages with, the ends of the slotted links 39; and'the connections 17 2l?227-22P are concurrently brought into operative conjunction. Under such conditions any reboundor separation of the vehice members ab'oveior beyond the normal load position imposes an upward pull on the. connector 229-22 and an outward thrust on the tubular bars 17''17 androcks bot1io tfthelevers 3 and 14: in a clockwise direction on their respective pivot ers, may continue supports 11 and 15 The downward movement of the inner lever 3 depresses the head 9 andsubjects the upper pair of supplemental. springs 2727 to anincreased bending stress; and the upward movement of the outer bridge lever 14 concurrently lifts the extremity ot the main spring 1: and imposes an increased'positive flexure on the primary member of the combination. The

mutual and conjoint reactions of the down? wardly flexed supplemental. springs27 and: the upwardly flexed main spring 1 and the cooperative diilerenti'al action of the two elements of the lever system, 3 Ma -e.

maintains anautomatic balance between the primary and secondary resistances of: the organization to rebound movements, and thereby equalizes the strain. on, the several parts of the elastic suspension system as-tlie latter is increasingly flexed by the separation of the body and axle parts. During'thisaction the lower supplemental spring 26 is, prevented from recoiling beyond its initially tensioned normal load position by the pull:

of'the rod'22 on the innerend of the piv oted clip support 29; and the point ofrconnection between these parts (22 and: 29): may be so adjusted, ifdesired, asto impose-- some added flexure on this third suppiemental spring during rebound movements;

so that in thiscase all of the spring; suspension elements are simultaneously. utilized to positively restrain and check any negative recoil of the system froninormal load 1108i?- tion. When this recoil action is unusually severe, the primary. and the secondary springs are flattened out nntila the-crossbolt 38 engages withthe upper face otthe main spring 1as shown in Fig. 6-'-and the intermediatepin 4-1 bears on-the-in-ner. 1

leaf of the lower supplemental spring 26. In this position of'the parts- (whichiresultsin a movement of the main spring from B to the inner lever 3 andthesecondary springs 26 27 27 are locked againstfurther downward reflection; but a continuationotthe rebound actionqvill rock the-outer bridge lever element 145", on its own pivot support: 15, and lift the outer ends of-the main spring 1' and the supplemental springs 27.

2". to a still higher positionlE (seeEig- 10). i

In this organization-as in the one first describedany movement of the systemin either direction from the point of static equilibrium imposes a positive flexu-ral stress on both the primary andsecondary resilient elements of the combination, and thereby progressively increases the initial tension orstrain to which those elements are subjected by normal load; and in both constructions the progressivelyincreased fle-xure of the supplemental springs are arrestedat predetermined pointsby si-,'

tive steps that onset with the: main s1In'ing-without interfering with the continued positive bending or straightening out" of the primary suspension n'ieniber of the systen'i. The fundamental operative characteristic of these mechanisms is the irreversible application of the kinetic stresses to the elastic support elements, in such manner that those supports-and particularly the main leaf spring-are never subjected to negative bending action that would tend to expand them beyond their initial load form and outline: but are, on the contrary. always increasii'igly con'ipressed or flexed in the same direction whenever the parts move in either direction from the position of static QQllllltll'ltUll. And a further characteristic of these systems is that the flexural movements of the main s 'iring' are always resisted by, and balanced against, the cooperative and conjoint movements of the supplemental springs-for displacements in both directions from normal load positionso that these prin'iary and secondary resilient members are mutually compressed against each other. and serve to mutually reinforce and stiffen each other against excessive distortion.

In order to check the natural tendency of the resilient system to oscillate about a mean position of elastic equilibrium, I preferably provide means for damping the free flexural movements of either one or both sets of springs, and thereby securing a more dead beat action of the suspension organization. In the construction shown in Fig. 4 the desired effect is obtained, in some degree, by the close frictional engagement of the interconnected portions of the divided lever system 31-ft; this engagement being capable of adjustment by the tightening or loosening of the nuts on the cross bolt connections 15-16. In the construction shown in Figs. 5 to 8 the area of contact between the lever elements 3 and 1.4 is considerably increasedby the provision of the extensions 4-2 on the lever member 3"-and an added restraint to any elastic oscillation of the system is secured by the peculiar funtional action of the long pliable supplemental leaf springs 26 and 27-27. hen the springs are flexed there is a relatively large sliding movement between their superimposed leaves; and this sliding motion is resisted by the friction between the plurality of spring engaged surfaces that are subjected to greater and greater pressure contact as the tlexurc increases. The frictional damp ing action thus produced may be augmented to any desired extent by the use of a larger number of binding clips-such as are indicated at 4L3 and t l-and also by corrugating the engaging surfaces of the superimposed leaves in the manner shown in the detail cross sectional view of Fig. 9.

The damping or retarding of the elastic flexures of the spring suspension elements diminishes the effect of the kinetic inertia, or momentum, of the oscillating parts and thus tends to reduce both the rapidity and the amplitude of the COlllPl'OSSlOll as well as the rebound movements of each main supplemental-spring combination. it understood, of course, that each end of the main cross leaf spring, 1, will be provided with a lever-controlled-supplcl'nental spring unit of the character above described; and that both of the cross leaf main springs (at the front and rear of the vehicle body) are preferably thus equipped. The damping and lengthening of the free period of \itn'ation of the spring supports tends to secure a more effective synchorizing action of the separate units. at the two sides and two ends of the vehicle, and thus prevent to some extent, the side rolling or end pitching of the body that results from a differential and non-concurrent compre sion or rebound of those units; and the decrease in the amplitude of elastic oscillation also tends to minimize the objectionable effects that are produced by such differential actions.

Each complete cross leaf spring organization-which comprises a pair of symmetrically disposed lever-controlled-spring units like those shown in Figs. 3 to 8-also prcsents a kinematical combination of parts that is very efiective in resisting and checle ing both the lateral rolling and the endwisc rocking or pitching of the vehicle tonneau. Any lateral sway of the body and main spring members-away from their normal central position with respect to the longitudinal axis of the running gearis in part restrained by the resultant shifting of the points of engagen'ient between the supplemental springs and the longitudinally rigid lever elements (3 or 3) and on the rebound movement, any such sway is further effectively resisted by the resultant increase in the tension of one or both of the connector elements 22 and 10 (or 22" and 39} as well as by the norn'ially balanced reactions between the reversely inclined shackle link suspensions 2-2 at the opposite ends of the main spring (see Figs. 6 and Iltl). The longitudinal rocking or end pitching of the body tends to twist the main cross leaf spring element 1 on its longitudinal axis; and this tendency is resisted in. part by the close engagement of the edges of this spring with the inner faces of the forked bridge levers M or 14, and in part by the symmetrical disposition of the twin supplemental springs l-l: or 272T) on the opposite edges of the main spring.

Figs. 11, 12. 13 and l t illustrate another embodiment of my invention, as applied to a front cross leaf spring support for a Ford type of car. In this exemplification of my improvements each supplemental 1 45, and. is. provided:- with an enlarged head 17 that engages-withthe inturned flange on the braeketsupport for the cup. These supplemental spring units are preferably arranged in pairs, symmetrically disposed one. on each side of: the main spring; and are supported on an intermediate flexible portion tlrereofby the bracket clip 6 (see Figs. 13iand 14); Eaehicell is providedwith a sliding piston-48 that moves freely inthe cup and is coupled'to the inner; extremity of a double arm lever; 3 by means of the one way bolt and stirrup connections 19- and cross bolt 51. The outer ends. of

the lever arms 8"3 are mounted on the shouldered extremities of the axleperch bolt 11 which also serves as a pivot support for the forked bridge lever 14-; and the latter member is coupledat its outer end to the adjacent extremity of the main spring 1, by means ofthe u-shaped shackle link 2". The. main lever- 3" is also providedwith a cross bolt 53, thatis o-peratively connected to an intermediate part of the link 2 by the rectangular frame 54andthe pintle pin 55. The side arms ofthe frame 54 are apertured or: notched tov receive the lower cross bar 56 of the stirrup bolt 57.; and the latter. is coupled: at its upper. end to-a bell crank bracket 58 on the body frame of the vehicle.

The operation of the last described con-, struetion is asfollows: WVhenthe parts are in the normal loadposit-ion shown in Fig, 11, the supplemental springs 1' are'conlined under. apredetermined initial tension with in the expanded cells 1546; and the lower edges of-the actuating lever 3" are held in pressure engagement with the overlapping portions of the bridge lever 1 1". \Vhen the system is subjected: to an increased kinetic stressand the main spring and axle members :are forced toward. each other-the engaged lever elements 3"'-14t are rotated as a unit, in a. counter-clockwise direction, on the axle perch supportll". Thismovement lifts the inner'ends of the actuating lever, and the connections 50-'1-9, and further compresses the supplemental springs between the upwardly. moving heads 18 and the dmvnwardly moving cap and clip parts 45-6 that are now held in iixedzrelation to the main spring 1. This action continues until the parts have moved from the positions B-b (as shown in full lines in Fig. 11 and as indicated in part in dotted lines in Figs. 12, 13 and 15) to thepositions C(; (as shown in full'lines in Fig. 12and indicated in part by dotted lines in Figs. 13 and 15) and it is then arrested by the engagement of the head 18 with the lower end of the=cap 46 showniin section in Fig.

12) andafter this .occursa-ny further compression, of the system is: resisted and checked by the continuedpositive flexure of, the reinforced main spring element 1.

During the closing movement. of the. spring suspended parts the system of, connections 5354i5556 -57.-'58-is inoperative or idiebecause of the free and upward movement, ofithe bracket 58-b-ut when the: members have returned to normalloadposition- (Fig. 11) thelower arm of the bracket 58 is engaged by the body. frame; and any. rebound'or: abnormal separation of the, body, and axle parts imposes an upward'pull on the stirrup bolt 5657. and; on the. cross frame 5 1, which tends to lift the link 2 and the outer ends, of the lever 14" andthe. mainspring 1; and thus again subjcetthe last named element to a. positive bending stress. But this action is necessarilyaccompanied by a reactive inwardpressure of the frame. 5% against the cross bolt;53,. which tends to imparta differential clockwise. movement to the inner lever element 32; and thislatter action depresses thfe headsoff the stirrup linkconnections 5.0; and thus again compresses, the supplemental springs at"- be, tween the downwardly moving caps--46 and the reverselymovingparts 484-5 that are now fixed relatively to themain spring-clip, 6. These differential and interhalanced flexures of the primary andv secondary springsmay be madevto progressively. in crease in varying predetermined ratios+ (when rebound movements occur) by. alter ing thekinematic relation between the. pivot pinconnections 11 -53*55- 56, and chang ing the, length of the rods 57. etc.; but when the parts have been carried to; the fullposi tions Bis-e, (shown in full lines. in Figs. 13 and 14s and also'indicated in thewliagramlo'l Fig. 15) the compression of the, supplemental springs 4" is arrested by the engagement of the head 1'? with the piston l-S atthe bottom ofithe cup 4:5(e. g, seeFig, 1'7); and when this occurs any furtherrebound movement is resisted. by the greatly; increased positive fiexure of themain spring alone which results from the upward swing of the; frame 5 1 on the locked leverpivot bolt and theresultant lifting ofthe shackle link 2 to the. position E Figs. 16 and 17 illustrate aconstruction very similar to that shown in-Figs. 11 to 15 inclusive. In this fourth exemplification of my invention there is amain side leaf-spring 1 and two supplemental springs 4 symmetrically disposed, one oneach side of the main spring, and mounted thereon in closed cell supports (comprising the clip connected cups 614 5' and: the. caps 46) inthe manner previouslydescribed (see also Figs. 13'and 14). The endsofgthe enclosed springs, 4 are operatively connected with theinner extremities of' the: actuating; lever i arms 3 3 by means of the heads 9, S)- which are adapted to engage with the ends of the caps 46-and the bolt and stirrup link connections 4)5O that are engaged at their lower ends with the sliding piston heads 48. The outer extremities of the arms Ztl3 are riveted or otherwise suitably secured to the torked shoe or bracket 61 which pivotally supported on the hanger bolt 11, and is provided with a pintle bolt 15 that carries the elbow portion of a belLcrank bridge lever 14. The outer end of this lever is coupled to the extremity of the main spring 1 by means of the U shaped shackle link 2; and the inner end thereof is connected to the relatively movable vehicle members (e. g., the body and axle parts) by the pair of parallel links 17 and the toggle links 21" and 22.

The kinematical action ot the organization just described is generically analogous to that of the construction shown in Figs. 4 to 8. lVhen the parts are in normal. load position B-b (as indicated in dotted lines in Fig. 16) the upper edge of the bridge block 14 is in engagement with the adjacent tace of the shoe block 61; and any increase of load stress-which results in a closing movement of the systemrocks the engaged lever elements l 6114 as a unit on the hanger bolt 11 and carries the parts toward the position C0 (shown in full lines in Fig. 17 and partly indicated in dotted lines in Fig. 16). This movement results in a joint compression, or positive fiexure, of the main leaf spring 1 and the supplemental springs 4; and the tension on, and in, these elements is progressively increased until the lower ends 47, of the caps 46. come into engagement with the heads 48 at the bottom of the cups 45. During this movement the toggle link elements 2122 assume the position shown at the right of Fig. 17; but this imposes no tension on the connectors 17 because of the lost motion between the slotted end or" the link 22 and its pintle bolt coupling to the adjacent elements of the linkage. But when the parts return to, and rebound beyond. the loci of static equilibrium the straightening out of: the toggle links 21- 22 exerts an inwardly directed pull on the connectors 17 and the pintle pin. 16, which tends to conjointly rock the luridge lever 14 downwardly (on the pivot bolt support 15) and the inner lever 3 upwardly on the main hanger bolt 11. The counter-clockwise downward movement of the bridge member 14 imposes an increased positive bending stress and flexure on the main leaf spring 1; and the cooperative upward movement of the lever arms 3 3 lifts the heads 48 and subjects the supplemental springs 4 to an increased compression against the relatively fixed caps 46. This last described action continues until the heads 46 are brought into contact with. the interengaged ends of the cups and. caps, 454647", (as shown in the full line positions .ll-e o't Fig. 16); and when this occurs any further separation of the body and axle parts rocks the bridge block 14 on a relatively tixed pivot support 15, and

sion elen1ent-is positively arrested by the links themselves, which thus serve to guard and protect the static system against undue distortion.

In the two illustrative embodiments of my invention, which are depicted in Figs. 11. to 15 and '16-17 respectively, the damping of the elastic oscillations of the spring system is effected by utilizing the supplemental spring cells (45-46 or 45 46) as elements of a fluid check mechanism which is actuated in one direction by liquid pressure and in the other direction by pneumatic pressure. Each of the caps, 46 and 46, is provided with a simple spring pressed valve 62 (which is shown only in the enlarged view of Fig. 16) that opens outwardly; and each of the piston heads 48 is provided with apertures 63 that are covered by the downwardly movable flap valves 64. The cups 45 are filled with a heavy viscous oil, or other suitable liquid, to the normal level of the cap heads 47 (when the parts are in the position of static equilibrium). When the pistons 48 are lifted, the valves 64 allow this liquid to pass vfreely through the aperturcs 63 and remain in the bottom of the cups 45 (as shown in Figs. 12 and 16); and on the reverse movement of the parts the valves 64 are tightly closed and the descent of the pistons-which controls the recoil or expansion movements of: the compressed springsis restrained and checked by the relatively slow and predetermined leakage of the 'oil past the edges of the pi.- ton heads. lVhcn the springs (4 or 4") are compressed from the opposite ends (by the downward movement of the caps 46 or 46) the valves 62 open to permit 01 the tree escape of air from the upper ends of the cells but when the recoil movement begins these valves closc, and the expansion of the cells, and of the springs, is then resisted by the partial vacuum created in the interior of the caps and the resultant increase in the external air pressure on their upper ends. In such a construction as that shown in Ill! Figs. 16-17, nearly all of the air above the level oi" the oil in the cups 45, will be polled during the downwart movement of the caps 46 (see cro ssection of Fig. 17); and the onlyair which can enter these caps on the upward movement is that which will leak in through the small clearance space around the rods 49. Under such circumstances the differences between the inner and outer air pressures may an'iountto lbs. per sq. in. or more; and it the diameter of each of the two caps is only three inches, the aggregate restraining pressure tending to prevent rapid recoil of the springs at may amount to nearly one hundred and titty pounds. lVith a ratio of lever-conjoined spring moven'icnts, such as may be readily used in the construction under consideration a restraint pressure of one hundred and fittv pounds on each supplemental spring unit may represent a damping resistance of one thousand pounds, or more, to the tree oscillation of the main spring and body parts; and this is amply siii'tlicient to eflectivcly check any rapid or free period vibrations of the heaviest vehicles under the most severe shocks of road travel.

The operative relationship ot the parts of the organization shown in Figs. 11 to 14 also presents an effective means for restraining both the side sway, or rolling. and the end rocking, or pitching, of the vehicle tonneau. The first mentioned movements are continuously resisted and checked by the reversely inclined and oppositely balanced thrust pressures of the supplemental spring elements l against the two side or end portions of the main cross leaf spring 1; and are also controlled-during rebound a-tionb v the diagonally directed reactive pulls of the rods, or links 57-57 on the opposite s des-1 of the vehicle body. The longitudinal rocking or pitching movements-which tend to twist the main cross lent springs on their longitudinal axes-are i .ined, as before, by the engagen'ient of the side faces of the main spring. and of the shackle link 2". with the rigid hollow bridge traiue 5a and its supports; and also by the balanced pressures of the twin secondary springs 4t on the opposite edges of the primary resilientelement.

In the construction shown in Figs. 1.6 and 17 the interconnected spring and lever elements are braced against relative lateral displacemeut-and against the longitudinal or axial twisting of the side leat main spring which accompanies lateral. rolling: of the vehicle bodyb v the mounting oi the lever suspension elements ll2 etc. between the rigid side walls of the pivoted bloclt (i1. and by the syujnnetrical positioning of the twin supplemental spring units on the opposite edges of the main spring member 1 and the endwise'sway of the tonneau on its elastic supports is also, restrained, to some degree, by the crossconnections between the ends of the arms 3 "and the spring cell mountings on the main spring- (when the parts are strongly compressed as shown in Fig. 17,), and by the longitudinal tension imposed on the links 17, when the parts rebound above normal load position.

In the organization shown in Figs. 18, 19 and 20 each ot the supplemental spring elements is made up of two counteracting volnte coils 4l l, which are mounted base to base on an intermediate clip support 6 that is suitably secured to the main cross leaf spring 1. These composite elements are preferably arranged in pairs-one on each side of the main spring as shown in Fig. 20 and are actuated by a double arm lever 3. which is engaged with the upper coils t l through the intervention of a cross head 51 and a common follower plate 65, and is con nected to the lower coils means of the one way bolt and stirrup link couplings 49*5(l and the individual follower plates 66-66. All of the secondary coils, l t and l l are held under a predetermined initial tensionand are prevented from expending beyond the normal load position shown in Fig. 18by the stop bolt 67 (which engages at its opposite ends with the clip 6 and the upper follower plate 65see Fig. 1.9), and by the stirrup bolts 5.0 which are secured at their lower ends to the plates 66, and are provided at their other extremities with elongated heads 68 that are engaged both by the lower ends of the bolts 49 and by the upper 'tace of the spring bracket sup.- port 6 (see Fig. 18). The side arms of the lever 3 are held in proper spaced relationship by means of the cross head connections 5l 69 and the shouldered ends of the axle perch bolt 11, on which this rocking member is mounted; and a second U shaped bridge lever 14-. is flexibly, secured to these arms by the cross bolt and the nut and washer connections 7071 (see Figs. 19 and The outer extremity of the bridge member 14; is coupled to the end of the main spring 1 by the forked shackle link 2; and the upper side edges of this auxiliary lever element are provided with segmental grooves 72 72 that are adapted to receive a pair of flexible connectors 7373, which are secured at their outer ends to the said lever. and are connected at their opposite extremities with the relatively movable axle and body members by the guide pulley 74 and the adjustable eye block 75.

The general mode of operation of the last described embodiment of my invention is substantially the same as that which characterizes the previously described exemplifications thereof. lVhen the parts are in normal load position (Fig. 18) the cross bar, of the U shaped bridge lever 14, is in engagement with the arms of the lev member 3; and the head, 51, oi the letter is operatively connected to the opposite e.\' trcmities of both sets of the initially t nsioned supplemental springs i and t hen the body and axle parts are 'lorced toward each other, by an in :rcased kinetic load or compressive shock. the lever system. 3 -l l. etc. is rocked as a unit on the axle perch bolt 15; and the head 51 is littcd. thereby raising the lower follower plates cc and compressing the supplemental springs e against the oppositely moving; main spring clip support (3. This compassion of the lower secondary springs is progressively increased the parts move from the positions BZ) (shown in full lines in Fig. 18 and partially indicated in the dotted and diagram lines of Figs. 19 and 21) to the positions C@ (see Figs. 19 and 21); but is arrested when the edge 01 the cross rih 60 engages with the lower side of the nepressed main spring; and after this occurs any further closure of the system is resisted by a flexural bending of the main spring alone. When the parts rebound above the position of static equilibrium. tae resultant separation Oiii the body and axle members, 74 and 75. imposes an inwardly directed pull on the flexible connectors 7373 which tends to impart a differential clockwise rotation to the two lever elements 3 and 143 (see Fig. 21) and thus move the said elements toward the positions Ec (shown in full lines in Fig. 19 and in diagram in 21). The clockwise swing: of the lever lel" on its pivot support 15 -li its the outer end of the main spring 1 and therel y imposes an increased fiexural strain thereon; and the concurrent or cooperative movement of the lever 3 (on its pivot bolt 11) deprsses the head 51 and thereby compresses the supplemental springs 4 against the upwardly moving main spring bracket G This movement is ultimately arrested by the cneapgement of the central part of the follower plate with the upper face of the clip 6' after which the secondary spring-lever tem, El -4;, is locked in position relatively to the primary suspension element: and any further separation of the body and axle parts is resisted by the continued upward swing of the bridge and shackle linl: connections 1 l- 2 toward the position R (see Fig. 21), and the resultant rapid increase in the positive bending strain imposed on the outer portions of the main leaf spring.

The construction shown in Figs. 19 to 21 is not provided with any means for damn ing or retarding the free elastic oscillations of the system; and in that respect it t ii. to present all of the specific clr'iracter' of the previously described ei'nbodimente of my invention. This construction does, however, present ahinenudical cim'lhination of parts which will cil cclively resist both side sway and longitudinal twisting of the cross leati main spring, a: l which will therefore, to that extent. res on the lateral rolling and the end pitching of the vehicle body on its elastic supports.

Figs. :22 and 23 illustrate another exemplilication of my present improvements, which possess certain specific 't'catnres oi, advantape that have not been heretofore described. in this exemplil'iration each supplemental spring unit comprises two conical or volute coils i -4; which are supported-one on each side (it the main cross leaf spring 1by a hanging bracket clip 6 that is attached to an intermediate flexible portion of the primary spring by the cross bolts 7777. The upper ends of these secondary coils are engaged by the head of the twin arm lever frame 3. which is pivotally mounted at an intermediate point in its length on the axle perch bolt 1 1. and is coupled at its outer end. (at 1:7) to the auxiliary bridge lever l i. The member ill is connected to the extremity oi the main spring 1 by the sha 'ldc lllll$-1 Q; and is also connected at a point near its pivot support 15 to the the vehicle by the spherical headed 57, the adjustable stirrup coupling 78. an d the semi-resilient bracket 58.

l action ot the organiyation shown in Figs. 22 and 23 is diagrammatically illustratcd in Fig. 24. When the parts are in the normal load position (Fig. 22) the lower edge of the bridge lever 14: rests on the pivot bolt support, 11". ot the lever B; and when the system is subjected to an increased kinetic compression stress, the relative approach ot' the main spring and axle members rocks the lever assembly (3 1 letc.) as a unit on the cross bolt 11 thereby dcpressing the lever 3 and compressing; the secondary coils l against their bracket support (3 This movement continues until the cross head of the lever 3 comes into engagement with the upper face of the main spring 1. (between the clip bolts 77 -77) and after this occurs the progressively increased compression of the supplemental springs is arrested, and any further approach oi the body and axle parts is resisted by the continued positive ilexure ot. the main spring alone. During this closingmovement of the system the connection. 57 -*5S etc, is inactive; but when the members return to the norn'ial position of static equilibrium. the various part5; of that connection are brought into tensioned engagement; and any rebound or separation of the members above or beyond the normal load position imposes an upward pull on the bridge lever 14? that is commun cated in part to the main spring (through the shackle links B 2). and in art to the outer extremity of the lever 23" Ell (through the cross bolt connection 15). This concurrent o-r conjoint aetion on the parts 1-1- 2 and 3 producesa differential rotation of the two lever elements in oppsite directions-the lever 14 being rocked in a counter-clockwise direction on its pivot bolt and the lever 3 being rocked in a clockwise direction on the axle perch support 1land these respective movements lift the end of the main spring (from position B to position E) and compress the secondary springs against the upwardly moving main spring clip 6 The downward, or clockwise, swing of the lever 3 and the concurrent and progressive compression of the springs 4 is arrested as soon as the head of this lever engages with the upwardly moving main spring (at position E-e) and any continuation of the rebound movement is thereafter restrained by the independent upward swing or" the lever l t (on the relatively fixed point 15) which carries the main spring to position E, and thus imposes a rapidly increased flexural strain thereon.

The'generic features of the last described construction are the same as those which characterize the organization shown in Figs. l to 21 inclusive. But the structural form and the specific functional action of the system shown in Figs. 22 to 2st differ from the cr'u'responding features of the preceding cxen'iplilications of my improvements in hav-' ing the conjoined lever elements so arranged, relatively to each other and to the main spring and body connections, that the sup plomental springs are compressed in the same directi0ni. e., dowmvardly-whenever the main spring moves in either direction (viz, up 01' down) with respect to the axle member. As a result of this arrangement the flexural motion of the secondary springs i follows the cooperative bending movement of the main spring when the system is compressed-and thus tends to accelerate or increase the downward movement of the main spring during such compression-and only opposes the movement of the primary resilient element when the body and axle parts rebound above or beyond the normal load position. The possib e range oil the angular movement, Z)0, or the lever 3 during CODIIJl'GSSlUH of the svstem, is therefore considerably greater than the angular range 7) c of this same lever during rebound; and the kinematical combination shown in Figs. 22 to 24 is, to that extent, not as effective, in quickly neutralizing the eli ect oi con'ipressive shocks, as are the combinations shown in Figs. i try-21. On the other hand the construction last described is a very simple and compact one; and it is, for that reasonQparticularly well adapted for use on low priced cars, or on closely built chassis frames, when the space available for the spring suspension system is very limited.

Fig. 25 illustrates a construction which is designed for use on a side leaf spring suspension, and which is, in many resp cts, substanti ally identical with that shown in Figs.

to 24. In this exemplifieation of my improvements the supplemental spring member comprises a pair of helical expansion coils s? (only one of which is shown in the sectional elevation) that are flexibly secured at their upper ends to the side bar 80 of the vehicle body, and are connected at their opposite extremities to the inner ends of a forked, or two armed, lever 3 and the latter member is rotatably mounted, on the main hanger bolt 11, between the depending sides of a U shaped body bracket 81. An auxiliary bridge lever, 1d is pivoted, at 15 to an intermediate part of the lever arms S and is coupled at its outer end, (by the solid shackle link 2 to an extension bracket 82 that is bolted to the extremity of the main side leaf spring 1 The bridge lever 14 is also coupled to the axle member of the vehicle by means of the adjustable link and spring bracket connections 56-57 58 The cooperative action of the interconnect-ed lever-actuated-spring elements OI" this organization is substantially the same as that of the analogous combination shown in Figs.

and 23, and the successive relative positions of the parts are iudi ated, in both cases, by the diagram of Fig. 2d. hen the parts are in normal load position-as shown in full lines in Fig. 25-the edge of the bridge lever 1d is in pressure engagement with the cross bolt 11, and the springs 4 are then under sullicient initial tension to balance the upward thrust on the main spring shackle connections 8:'22. \Vhen the body and axle members are forced toward each other, by a kinetic increase in load stress, the connected lever elements, El -14, are rotated clockwise, as a unit, on the cross bolt l1 (thus moving the lever system from position, b, to or toward the dotted line positions cc) and the second ary springs L l are subjected to aprogressively increased tension that balanced against, and coacts with, the corresponding increase in bending strain in the main spring 1 When the parts rebound abovethe normal load position the connections, 56 58 are brought into semi-elastic tensioned engagement to exert a downward pull on the lever id; and this movement is transmitted, in part to the lever -to again rock this element toward the dotted line position C, and correspondingly expand the springs l and in part to the shackle link 2 to thereby depress the end of the main spring toward the dotted line positions Ec, and thus subject the primary suspension element to a cooperative increase in tlexural stress. ln both of these movements (of closure or of rebound) the downward swinp of the lev r 3 is arrested, at substantially the same point in its arc of motion, by the engagement of the spacer bolt member 83 either with the face of the main spring l or with the. edges of the tensioncd stirrup links 57. ll hcn this engagement occurs the lever-suppleniental-sprin system is locked in position with respect to the main spring; and any further dis ilacement of tl e oody and axle members is resisted and restrainei'l by the progressively increased bending strain in the main spring; alone.

Both of the last described organizatioin' (shown in Figs. 22 to 25 inclusive) presenta kineinatical. assemblage of connective elements that is effective in rest-raining both longitudinal and lateral displacements of the body with respect to the axle member of the chassis frame. In the case of cross leaf spring suspensions each end of the main spring will be provided with a supplcmcntah spring-lever combination like that sho vn at the left of and in the case of side leaf spring suspensions the opposite or opposing ends of the front and rear springs are connected to the body by the lever-linksprinn' mechanism illustrated in Fig.2. When the parts of either of these suspension systems are subjected to rebound stresses the body of the vehicle is held in centered ant. balanced rolatioi with respect to the axle supports by the symmetrical action of the reversely ii clined tension connections 5'? or 57 at the opposite sides or the opposite ends of the chassis frame; and an added degree of transverse stability is ii'nparted to main spring elemei s either by the balanced pressure of the two supplemental springs d on the opposite edges thereof, or by the close sliding; arrangement of the tensioned stirrup links 57 with those edges. In the case of compressive movements these restraints to lateral sway or displacement of the spring connected parts are less effectivcand in that respect the systems of Figs. 22 to 25, are somewhat inferior to those illustrated in l i s. 4: to 'iuclus vclmt there is less necessity of guard] against rocking and pitching: actions when the body and axle nuts are pressed together than when they are thrown apart. by rebound stresses.

The (TOHStJ'HQllODS shown in Figs. 26 to inclusive, represent another species of organization that may no employed in applying; my invention to either cross leaf or sioe leaf spring suspensions. In these embodiments of my lIlN HOYQIHGHl S I dispense with any separate bridge lever clcir-cut (such as the one indicated by the left Jed numerals ill to let) and substitute therefor a shifting nilcrum support for one of the other elements the lever-actuated-supplemental-sm'iug con'ibiuation. The basic operative features of this second species of organization are substantially the same as those which characterize the *arious structural combination shown on the first three sheets of my (h'aivings; but it also presents certain individual features of construction and operation which will now be considered in detail.

In the arrangement shown in Figs. '20 to inclusive, the secondary resilient element or the suspension is made in the term of a single supplemental leaf spring i which rests, at its inner end, on the central portion of the main spring l, and supported, at its outer end, in a bracket clip 84-; and this bracket inen'iber is pivotally mounted at on the extremity of a double arm lever so, and is coupled to the end of the main spring by the shackle links Q Q".

The lever member 86 is rotatably supported on the axle perch bolt 11 and the side arms thereof are held in suitable spaced relationship (by the spacer connections 5(3-'-8, and the shouldered ends of the cross bolts 11* and 85) to engage closely with the guide block 87 that is bolted to the axle at the point just above its connection with the radius rod 88. The intermediate part of the lever is coupled, at 56' to the body of the vehicle, by the one way" bolt and stirrup link connections The operation of this mechanism is as follows: ii hen the parts are in the normal load position shown in Fig. 26, the spacer bolt 8 3*, of the lever 86, rests on the axle; and when the body and axle members are forced toward each other, he bra/ket 84 is rocked downwardly on the relatively fixed pivot bolt 85, and a progressively increased bending strain is thus concurrently imposed on both the main spring 1 and the secondary spring 4- This movement continues until the partshave moved from position 3-?) to pt ition C-c (see Figs. 26 and 29) or until the supplemental spring, F, has been flattened out into pressure engagement with the adjacent portions of the main spring 1; after which the two superimposed suspension elements act as one reinforced and sti'll'encd spring to strongly resist any further approach of the body and axle members. During this closing or compression action of the system the lever 86 remains fixed in position on the axle supports; and the sliding; bolt and stirrup link connection 5'? is inactive. But when the parts rcbound above the normal load. position B, the separation of spring connected chassis members imposes a pull on the one way connector between the body and the lever, 86, and rotates the latter, in a. clockwise direction, on the axle perch bolt 11 This movement lifts the pivot support, 85, of the spring bracket 84, and thereby again in- Too llt

In this construction the elastic oseilla-' tions of the resilient suspension members are damped by the sliding frictional engagementbetween the superimposed leaves of the long pliable supplemental spring 4 and this damping action can be increased, as desired, by the use of a larger number of binding lips, 44 etc., or by corrugating the engaging surfaces of the leaf [elements as shown in Fig. 9. During rebound movements this frictional restraint is further increased by the sliding engagement of the inner faces of the lever arms, 86, with the surfaces :of the guide block 87; and this effect can be varied, at will, by suitable adjustment of the cross bolt connections 11 56 83 and 85, or by the interposition of fibre linings between the adjacent faces of the lever arms and the block. The inwardly directed pressures of the two suppleuziental leaf springs, on the opposite sides of the vehicle, against the convex upper surface of the main cross leaf spring, presents a very effective resistance to any lateral swing or (transverse rolling of the body; and this restraint is further suppleinentedduring rebound movements when it is most neeessary-by the symmetrically and reversely inclined tensions in the connections, 57 861l between the opposite ends of the axle and the adjacent sides of the tonneau frame. In the parti ilar arrangement of parts illustrated in F 26 to 28 {there no special. means for preventing axial twisting of the main suspension spring-which is produced by, .or results from, the longitudinal pitching of the vehicle body-but this effect is resisted.

to some intent, on extreme movements of the parts, by the extended contact engagement between the adjoining portionsof the primary and sefzondary spring members; arl the restraint under consideration, may be rendered very effective by making each siuyplemental. spring" 4* in two parts, that are synnnetrically disposed on the oppc-isite edges of the main spring, and are joined together at various points by clips and cross bolt-s, in the manner illustrated in the upper portion .of Fig; 5,, .6 and 7 e., like the twin spring elements 2Z --2'Z-3337 as etc),

The organization shown in Fig. the same species as that shown in .l i

tails of structi-u'al form. In this ninth illus-,

trative embodiment of my invention the supplemental spring element comprises a single volute or beehive coil l the boss of Which is uuiunited in a recessed block 90 that is bolted to the side bar of the tonneau frame. The lower end of this secondary coil is operatively connected to the inner extremity of the forked bracket lever 84:, thnough the intervention of the follower plate and the cross (spacer) bolt 51. The lever frame is coupled to the end of the main side leaf spring 1 by means of the U shaped shackle link 2; and is pivotally supported its outer extremity on the pintle bolt The pivot support 85 is carried by a second lever 86, which is rotatably mounted on the ba bolt fll. of the block 90, and which is in its angular movement by the stirrup frame 8,7 that is also bolted to the side bar of the vehicle tonneau. The intermediate portion of the lever 86 is connected to a semi-resilient axle bracket .58, by means of the cross bolt 56 and the links 57 57 that are closely engaged on their opposite sides by the adjacent edges and faces of the main spring 1 and the double arm lever 8 L.

The coopeatire action :of the lever-controller V k elements of this last described organiaaiion is substantially the same as that of the system shown in Figs. -26 to 29, and it may therefore be very briefly described by stating-: First, that a compressive stress will noel: the lever frame 84 upwardly, on the relatively fixed fulcrum support 85 and thereby subject the supplemental spring to a progressively increasing compression, which will be arrested when the parts have been moved from the full line positions, BZ to the dotted line positions G-c, and the upper edges of the lever frame 84 have come into eng genrent with {the lower end of the stirrup g do block 87 second, that an expansion or rebound of the systeinfibeyond normal load position-will bring the connections 57-58 into operation and rock the lever 7 8G downwardly on its pivot support 11*, thereby subjecting- :tlhe inain leaf spring to an "increased bending s mess and reac-tively imposing an increased (compression on the supplemental spring 4 and that this action wi ll continue until the pants have moved to the lowermost dotted line positions 13-6, and the lever 86 has come into contact with the :lowercross bar of the stirrup frame 87*; and third, that the elastic oscillations of the system may be frrictionally damped by the sliding engagement between the contacting faces and edges of the elements 8687 and 57-8 l 1 If the opposite ends of the front and rear gnieinbers, of aside leaf spring suspension, are each provided with a supplemental levercontroillechspring :unit

clined connector elements, 5'4"", of these units will also act to restrain and check longitudinal rocking or pitching of the body when the latter rebounds or moves away from its axle supports.

Figs. 31 and 32 illustrate a modified type ot the species of organization that is shown in Figs. 26 to 30 inclusive. In this type ot my improved shock absorber construction the extremity of the main spring 1 is suspended directly from one nd 01? a supplemental spring element al by means oi the cup shaped follower plate 65" and the long shackle links 2 The opposite extremities ot the secondary coils P are supported on the outer endL of a L shaped lever frame 86, which is pivotally supported, at its inner end, on the aide perch bolt 11, and is coupled, at an intermediate point of its length, to the body of the vehicle by neans ot the cross bolt 56" and one way bolt and stirrup link connections 5'5 A channel bracket 537 is bolted to the brake drum ot the rear a zle-in place of the usual shackle lint: bracket at that point-and serves guide, and if desired also trictionally restrain, the arcuate movement of the lever l'rame 86 on the pivot support ll The operation of this last described system is as follows: lVhen the parts are in the position of static equilibrium (as indicated by the dotted lines, B b, of Figs. 31 and 32) the outer end or" the lever irame So rests on the lower shoulder or the guide bracket 87 and the normal bending strain in the main spring is transmitted to and carried by the initially tensioned supplemental coils l When the body and axle parts are forced toward each other, by an increased kinetic load, or compressive shock, the secondary springs are further compressed against: their relatively stationary lever support, and the; parts assume the positions (C-o) shown in full lines in Fig. 3l;this progressive compression of the supplemental resilient element being arrested when the main spring comes into engagcn'icnt with the cross (spacer) bolt 56, and is thus prevented from further bodily movement toward the axle supports. Jitter this engagement the part of the main spring between the bolt supports 56 (on the two sides of the vehicle) acts alone, as a shortened and greatly stitl'ened leaf spring, to resist and restrain any further closing of the system. lVhen the members return to, and rebound above the normal load position (l3---Z)) the ends of the bolt and link connections 57 are brought into tensioned engagement; and the lever frames S6 are lifted toward the full line positions E-e ot Fig. 32; thereby imposing a directly balanced and progressively increased stress and strain on both the primary and the secondary springs, 1 and el ;-and this progressively increased tleXure, ot the two interconnected resilient suspension elements, con; tinues until the supplemental spring coils are compressed sufficiently to bring the central stud 9i oi the lever support into contact with the follower plate 65*, after which the further upward swing of the lever, 8th, is only effective in producing a continued positive bending of the main spring alone. There is no damping restraint imposed on the elastic oscillations or this system during conwressive or closing movements of the relatively n'iovable body and axle mem bers; but in the rebound or expansion movements thereof the free period and tree amplitude of such oscillations may, if desired, be trictionally retarded by a close sliding engagement between the outer heads of the rocking lever frames 86 and the channeled guide brackets 87 whicn may, in such cases, be faced with fibre or leather sui ab e liners for increaping the frictional r nee. lVhen the parts are under compressive stress the lateral sway, or transverse rolling of the, vehicle body, is resisted by the sym n'ietrically, and oppositely, inclined lines of pressure engagement between the two ends of the main spring 1 and tie parts ot the obliquely disposed lever frames that are engaged, either directly or iiulirectly. therowith; and when the members rebound, above normal load position, the tonneau and axle parts are held against relative lateral displacements by the symmetrical tensions iniposed 0n the, opposite sides of the vehicle body by the connections 537 The only provision for checking t-rai'isverse r axial twist; ing of the main sp1.'ingand thus resisting longitudinal pitchingis that aftorded by the engagement between the opposite edges ot the said spring and the adjacent side arms of the lever frames 80.

Figs. 33 and 34: illustrate an application ol the form of construction shown in Figs. 31 and 32 to a side leaf spring suspension. In this embodiment of my iinprovemen the supplemental spring element coinprieais two helical coils l-" i, which are Supported. one on each side ot the main spring 1*, by an inverted T-shaped hanger bral'lcet 92 that is pivotally connected, at its upper forked extremity, with the end eye of the said main spring. The upper ends of the secondary springs 49 are mounted in recessed heads of a follower lJlUt'h 93, which is provided with an elongated collar hearing that slides longitudinally on the leg of the T shaped bracket 92. The heads ot this follower block are engaged by the outer forked ends 9-l9al ot the double arm lever frame 86, which is pivotally mounted. at an intermediate point in its length on the main spring clip bolt ll, and is coupled, at its other end, to the body of the vehicle by the flexible connector 57 in the northe mal load position of the parts shown in full lines in Fig. the members 93 and 94 are maintained in pressure contact with the inner forked heads, 95-95, of a U-shaped bracket 96, that is bolted rigidly to the end of a scroll spring support 97 and each of the heads 95 is preferably provided with an auxiliary guide rod 98 which extends downwardly through cooperating collar hearings in the relatively movable supplemental spring supports 92 and 93, and assists in maintaining those parts in proper axial alignment. \Vheu the system is subjected to an increased kinetic load stress, the body and axle parts approach each other and the bracket support is lifted toward theheads 95; and the supplemental springs 4-4l are thereby compressed against the relatively fixed upper follower plate and lever meinbers SS-94, This secondary spring compression gradually increases-4n conformity with the corresponding positive flexure of the main spring 1 until the central collar on the block 93 and the lower head of the hanger 92 are brought into contact with each other; after which the intercngaged elements 9293, 94-95 act as a solid or nonresilient shackle link connec tion between the end of the main spring and the scroll support 97, and any further approach of the relatively movable chassis members is resisted and restrained by the continued flexure of the main spring alone. \V-hen the members return to the locus of static equilibrium the connector '57 is brought into tensio-ned engagement with the parts to which it is coupled; and any rebound of the body and axle members, above normal load position, imposes an upward pull on the inner end of the lever frame 86, which results in a counter-clockwise rotation of that frame on its pivot support 11 This movement depresses the follower plate 93 and imposes an increased compression on the supplemental springs i, which is transmitted, through the braclret connection 92, to the end of the main spring, and thereby again subjects the latter to a correspondingly increased bending stress and strain. Thesecooperative and conjoint flexures of the primary and secondary suspension elements (on rebound) are progressively and concurrently increased until the parts have been moved from position B to positions E-e (as shown in full lines in Fig. 34: and partially indicated in dotted lines in Fig. and the central bearing collar of the follower plate 93 has been brought into engagement with the head of the T shaped bracket 92'; but after this the supplemental springs are locked against further eoi-n'pression, and the continued separation of the body and axle members is resisted and checked by the greatly increased positive bending of the outer portion of the main spring alone. During these successive movements of the system the lateral sway or transverse rolling of the body on its elastic supportswhich tends to twist or tirn the side leaf springs on their longitudinal axes-is restrained by the ba l anced pressures of the supplementalspringlever connections on theopposite edges of the said main springs; and when the parts are subjected to rebound stresses the longitudinal pitching of the toiii-neau, on the front and rear side leaf supports is resisted and checked by the tension of the conne::tor elements 57 All of the various spring suspension systeirs hcreinbeforc described are characterized by the same basic principle or mode of operation; i. -e., the elastic balancing and the ultimate absorption of both compression and rel'iound stresses and shockswhich are si-iperiniposed on the normal or static load by the syst-en-iby a positive increase in the in. al tensions or iiexnres of two or more resilient elements, of vary flexibility, which are conjoined in such n'i-anner that the lighter stresses, and the smaller displacements of the pains. are resisted and checked in large measure by the lezrural action of the more pliant, or secondary, springs, while the more severe stresses and the larger oscillate 7 movements, are resisted and arrested, first, by the cooperative increased flex-are of both the secondary and the primary springs, and second, by the locking of the secondary springs against further compression and the continued and augmented compression of the primary springs, alone. Or stated in anotherway, the various shock absorber organizations, that exemplify my present invention, are all characterized by a generic mode of action which involves the posi iv-e conjoint compression, or increased flexure, of two or more interconnected springs diiferent strength, whenever the rela i vol-y movable --spring supported parts move in either direction from the position of static equElibriun'F-as distinguished from the usual operation of primary and sec ondary spring combinations, in which rebound movements are accompanied by a decreased strain, and a recoil or negative flexure, in one Or both of the resilient suspension eleme-nts and which further involves the arrest of the progressively increased compression of the more flexible supplemental spring, or springs, when the movements in either direction, have attained a certain a-n'iplitude, and the continued positive tenure of the stiffer main spring member by further movement beyond such points of arrest.

From a structural standpoint the various illustrative embodiments of my invention also present certain generic features of correspondence All of the organizations here lOO in disclosed comprise a combination of a relatively stiti resilient support elements (generally designated as a primary or main spring) with a relatively flexible secondary or supplemental suspension member in series therewith-so that the stress and strain on the one element is transmitted to the other and a system of lever connections for conjoining, or operatively couplin both of the aforesaid units with the two relatively movable-spririg-supported parts in such manner that any movement of the said parts, in either direction from the position of static equilibrium, will impose an increased flexre, or compression, on both the primary and the secondary suspension members. The different exemplitications of my invention that have been described, present several forms of lever-connections, that are adapted to perform the generic function last mentoned; but all of these conjunctive systems comorise a lever, which is pivotally mounted on one of the relatively movable parts of the organization and is coupled to the other of the said movable parts by a flexible or one way connection that is active or operative only during rebound mo ements; and further comprises continuously actin elements that serve to engage the lever with. both the secondary and the primary springs and to flex the latter in the same direction, i. e., positively, whenever the spring supported members move in either direction from normal load position. All of these systems likewise contain stop elements, which are adapted to arrest the action of the lever system on the secomlary spring-and prevent "further positive compression of that elenu2nt-when the displacement movements have attained a. certain predetermined n'iagnitude; but which do not interfere with the continued 2 ction of the system, in progressively increasing the fiexure of the primary spring, when the movements exceed that amplitude. The general functional arraugcment of lever-connections constitutes what may be termed an irreversible springcontrolling s y stem; viz, a system which prevents any reflexing, or expansion, of the elastic support elements beyond their ini tially tensioued normal load form but which lll!] )OStS, on the contrary, a one-way positive and progressive increase in the elastic strain on those elements whenever the parts supported thereby are kinetically displaced, in either direction, tom the position of static equilibrium. It is to be understood that the tern'is irreversible-control mechanism, or irreversible control linkage, etc., which are hereinafter used in the claims, refer to a kinematical assemblage of lever and link connections, between the primary and the secondary springs and the movable members supported thereby, which present the functional and result-attaining characteristics last describec i. e., the word irreversible is used to designate the functional nature of the control action that is exercised by the mechanism or linkage, and not to describe or indicate any fixed structural relationship, or any particular direction of movement, of the linkage elements.

It will be further understoodtrom a comparative review or the various illustrative constructions hereto-tore disclosedthat the basic features of my invention may be embodied in a number of varied species and types ot elastic suspension systems; and the utilization of my improvements, in whole or in any desired part, is not dependent upon the employment of any specific form, or any specific nmuber, of prin'iary and secondary springs. Figs. 4, 5 to 9, 11 to lt, 18 to 20, 22, 26 to 28, and show exemplilications at my invention as applied to main cross leaf spring suspensions; Figs. 1617, and 30 illustrate applications oi my invention to main side leaf spring supports of the semielliptic type; and Fig. 33 depicts an embodi ment oi my improvements in which the primary spring unit is of the three-quarter elliptic, or scroll support form. lhe diii'erent figures of my drawings show a still greater variety of supplemental or secondary suspension members of both the leaf spring and the coil. spring type, and oi both the single or multiple Form of construction. Thus l igr'. 26 and 3t) illustrate the use of a supplemental suspension unit which consists of a single spring (in one case a leaf and in the other case a. coil spring) which flexed or compressed :t'rom the same side, or in the same direction, by either the closing or the rebound movements of the system. Figs. 22 and 25 show a secondary s tiring unit which com prises a pair of helical coils (of either the compression or the expansion town), which are likewise flexed in the .Jame directioni. e., by a downward movement of the ends that are connected to the actuating lever system-whenevcr the spring supported parts are moved in either direction from normal load position. Figs. 31. and 32 depict another single coil supplemental spring unit which is increasingly compressed in revm'sc directionsi. e., by alternate movements ot, the opposite endswhen the relatively movable vehicle members are displaced in opposite directions from the point of static equilibrium. Figs. l, 11 to 14, 16-17. and 33 present examples of secondary suspension members of the inulti'de coil doubleactiug spring form, which are so connected to the irreversiblecontrol-linkage system, that they are compressed from opposite ends-and pro-canto in opposite dircc tions-in their alternate restraint oicom prcssive and rebound movements. And Figs. 5 to 9, and 18 to 20 illustrate the use of supplemental. suspension units which com- 

